Where air quality data, rules could get confusing

It is more than a little confusing – the San Joaquin Valley Air Pollution Control District’s new wood-burning rule.

Eight individual counties make up California’s San Joaquin Valley. For the first time in the Valley and begun on Nov. 1st, is implementation of a new district-wide rule.

In its Nov. 3, 2014 news release: “Air officials issue first fireplace prohibition of season for central, southern counties,” the air district emphasized, “Check Before You Burn No Burning Unless Registered wood-burning curtailments are in effect for Tuesday, Nov. 4 in Madera, Fresno, Kings, Tulare and the Valley portion of Kern counties. It is the first curtailment of the season.

“The daylong mandatory curtailment that prohibits the use of unregistered devices because of poor air quality is in place through midnight Tuesday. The curtailment applies to burning wood, pellets and manufactured fire logs in unregistered residential fireplaces, stoves and inserts, as well as outdoor burning devices such as fire pits and chimineas.” (Emphasis is the air district’s).

So, it wasn’t but two days after this “conditional” rule went into effect that the first wood-burning curtailments or prohibitions applied.

Not surprising since the Valley is known for its sooty wintertime air, not to mention summertime skies that are notoriously smoggy. In fact, 30 percent of fine particle pollution hanging in the Valley’s wintery air can be attributed to the burning of wood from residences. Atmospheric inversion layers (typical this time of the year) and area topography (the Valley is bounded on the east, south and west by ranges of mountains) only serve to exacerbate such poor air quality conditions.

Meanwhile, the air district farther on in the release specifies: “There are two exceptions to wood-burning prohibitions: If the residence does not have access to natural-gas service, even if propane is used; or if burning solid fuel is the sole source of heat for the residence.”

Moreover, a new of way of alerting residents as to expected or forecasted air conditions is via so-called “declarations” that have been put in place. These are:

“No Burning curtailment: No one can burn at their residence.

“No Burning Unless Registered curtailment: Residents must register their emission-compliant wood-burning device with the District by visiting www.valleyair.org/CBYBregistration in order to use this device during this declaration.

(Sources: “Air officials issue first fireplace prohibition of season for central, southern counties,” San Joaquin Valley Air Pollution Control District, press release, Nov. 3, 2014 and “Air officials issue first fireplace prohibition of season for northern counties,” San Joaquin Valley Air Pollution Control District, Nov. 4, 2014).

Relatedly, Mark Grossi in “San Joaquin Valley air turns unhealthy,” in no uncertain terms noted the pollution is particularly problematic in the four Valley cities of Bakersfield, Clovis, Madera and Visalia.

Keep in mind also throughout the entire eight-county region that, declared, is the “No Burning Unless Registered” condition.

Now, as for the confusion, take a look at the air district’s Real-Time Air Advisory Network (RAAN) data for Central Bakersfield for Thursday, Nov. 6th. These are the hourly (as of this writing) PM 2.5 readings (in micrograms per cubic meter of air):

12 a.m. – 77

1 a.m. – 73

2 a.m. – 66

3 a.m. – 66

4 a.m. – 63

5 a.m. – 58

6 a.m. – 68

7 a.m. – 71

8 a.m. – 69

9 a.m. – 103

Notice at no time during these hours was air anything other than unhealthy.

So, conditions in Central Bakersfield being what they are on this (Thursday, Nov. 6th) day, why not the “No Burning” curtailment designation?

In both these instances, I fail to see why the “No Burning” restriction wasn’t issued.

So you know, a level of fine particulates of 103 micrograms per cubic meter of air is almost three times that of the federal 24-hour PM 2.5 health standard of 35 micrograms per cubic meter. Air where PM 2.5 concentrations are above 35 micrograms per cubic meter – corresponding to an Air Quality Index of 100 – is deemed “Unhealthy.” For purposes of the Valley, meanwhile, PM 2.5 at 20 micrograms per cubic meter is the new threshold.

I suspect before the season ends for bans on wood-burning on Feb. 28, 2015, we’ll be seeing many more of these wood-burning bans in effect.

2 thoughts on “Where air quality data, rules could get confusing”

The federal air quality standards (approved in 2006) are 35 ug/m3 – 24-hour average and 12 ug/m3 – annual average. The 24-hour averaging period allows for higher levels than 35 during some hours of a day, but your question is a reasonable one. For the hourly data you reported for Nov. 6, compliance with the 24-hour standard would be achieved if the average PM2.5 concentration during the hours from 10am to midnight was 9.0 ug/m3. This is possible, but unlikely. Yesterday the 24-hour average at the Central Bakersfield monitor was 58.7 ug/3, but last Saturday it was 3.3 ug/m3. To date, no air quality agency as adopted a 1-hour standard for PM2.5, and health effects data indicate that more than one hour of exposure to elevated concentrations of PM2.5 are needed to produce observable adverse health effects.